Electronics Forum | Thu Aug 08 15:16:03 EDT 2002 | OhioD
A "Pumpprint" stencil refers to a thick DEK stencil with pockets routed-out on the underside, so it will clear any THT leads, paste/glue deposits, etc., and not squish them. It's called pummprint because it was developed to use the ProFlow-type head
Electronics Forum | Tue Aug 06 22:20:32 EDT 2002 | Computer
Hi , I am currently faced with a problem with the via hole on the component pad. The customer does not allow plugging of the hole and enlarging the stencil pad hole size or thicker stencil size may cause bridging to the component next to it.
Electronics Forum | Tue Aug 27 08:12:35 EDT 2002 | jmaruska
Do you have some experience with solder paste WS1208. What is the "best" conditions for printing process? I mean type of stencil, apertures, squeegee. Do you have original data sheet of this solder paste? - life time, working time on the stencil, sh
Electronics Forum | Thu Aug 29 13:03:13 EDT 2002 | lysik
You have may have already checked this but verify stencil design (aspect ratio) and make sure you are using the correct paste (mesh size) Also look at perint pressure. up to 2 lbs per inch of blade used. You may also want to use a slow break away whe
Electronics Forum | Fri Sep 13 14:21:49 EDT 2002 | blnorman
Run a test, but in our experience, yes you can reuse the paste. We ran tests on paste that was left on the stencil at the end of second shift, we put the paste back on the stencil the next day on first shift with no problems. You definitely want to
Electronics Forum | Mon Dec 16 21:34:05 EST 2002 | grantp
Hi, Yes, the stencil does touch the PCB. Is there another method? Sorry to sound a bit dumb on that, however I don't have a lot of experience with automated stencil printing, and manual has been working well up to now with this BGA. Regards, Gra
Electronics Forum | Wed Dec 18 01:37:39 EST 2002 | Steve
I dont know what kind of screener you use but my 1st impression is that the board and stencil are separating too fast,the paste doesn't have enough surface tension to stay on the board, you're tearing the paste off the board. If you can, slow down th
Electronics Forum | Wed Jan 08 14:36:44 EST 2003 | davef
It depends on your product requirements. We don't like to print off-pad, because: * Tough to control the amount of paste that squirts onto the board, because the aperture is not gasketed to the pad on the board. * Some paste that squirts between the
Electronics Forum | Wed Feb 26 16:06:34 EST 2003 | slthomas
Something else I just thought of, and MikeK touched on it briefly, is what you'll be cleaning. If you need to be capable of removing both epoxy and solder paste, for instance, you need to look at chemistry and processes that will clean both, and the
Electronics Forum | Thu Mar 06 10:57:28 EST 2003 | Mark
What are the recommended stencil apertures for a TSOP40. Lead pitch 0.48mm & lead width 0.21mm. And direction of squeegee print over the aperture? Recommended Stencil thickness? Recommended aperture reductions? Recommended pcb pad sizes? Recommended
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